Electric heater



Sept. 18, 1928. 1,684,450

J. H. KNAPP ELECTRIC HEATER Filed Aug. 27, 1926 2 Sheets-Sheet 1 Sept. 18, 1 28. 1,684,450

J. H. KNAPP ELECTRI C, HEATER Filed Aug. 27, 1,926 2 Sheets-Sheet 2 WITNESSE5 Patented Sept. 18, 1928.

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JAMES H. KNATPP, F LOS ANGELES, CALIFCRNIA. ASSIGNOR TO JAMES H. KNAIPP COM- PANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

ELECTRIC HEATER.

Application filed August 27, 1926.

This invention relates to electric heaters, more especially to domestic heating appliances for heating air in rooms, and it is among the objects of this invention to provide a heater of simple construction which may be embodied either in the form of a wall or portable structure.

Another object of this invention is to provide an electric heater which shall be adapted to circulate a large volume of air through its heated parts so as to afford relatively large heating capacity without the utilization of direct radiation. which is the general principle upon which most electrical heaters are constructed and operated.

In accordance with the invention the heater is constructed of a housing adapted to support a plurality of vertically disposed heatin; plates of refractory or other suitable material and a plurality of electrical heating or resistance elements disposed between the plates in such manner that little or no direct radiation of heat is effected by the elements. The arrangement of heating plates and resistance elements and their manner of mounting in the housing is such as to make provision for the circulation of a large volume of air from the bottom to the top of the heater between and around the heater plates and around the heating elements. and thence into the space it is desired to heat.

In the accompanying drawings constituting a part hereof and in which like reference characters designate like parts. Fig. 1 is a vertical sectional view partially in elevation of an electrical heater embodying the principles of this invention; Fig. 2 a longitudinal sec tional View thereof; Fig. 3 a front elevational view with a part of the front guard or grating broken away to illustrate the heater plates and the heating elements; 4 a vertical sectional view illustrating a portable type of heater embodying the invention; Fig. 5 a similar view of a modification of the heater shown in Fig. 4; Fig. 6 a perspective View of a corrugated sheet metal section which may be utilized in place of refractory reflector plates; and Figs. 7 and 8 vertical sectional views showing modified forms of heaters in which the reflector plates are broken up and arranged to constitute louvers.

Referring to Figs. 1, 2 and 3 of the drawings, the structure there illustrated comprise a frame or housing 1 built into a Wall open- Serial No. 131,899.

ing or fireplace 2 as a permanent or removable structure. The front of the frame is provided with a grid or grating 3 secured in a suitable manner at its periphery to wall 2 or the housing 1 of the heater. A rear refractory plate 4 having a flat intermediate portion 5 and provided with ribs 6 on its forward face, is supported by and secured to the housing 1. The plate 4 is curved at its upper and lower edges to conduct air upwardly through and forwardly at the top of the heater. A front refractory plate 7 preferably having ribbed faces 8 and 9 and being smaller in vertical extent than the rear reflector plate, is secured by brackets 10 and 11 to the grid 3 at its central region leaving a relatively large space at its top and its bottom portions for the passage of air.

A plurality of heating elements 12 are disposed between the rear and front plates 4 and 7 below the top and above the bottom edge of front plate 7 These elements are electrical resistors of suitable capacity and may be secured between spring terminals 13, Fig. 3. attached to terminal blocks 14. The blocks are provided with terminals 15 for connection to conductor elements 16 leading to a source of electric current supply.

As shown in Fig. 2, rear refractory plate 4 is provided with ribs 6 on one side only and is built up of sections provided with overlapping joints 18 for aligning them in their assembled positions. Similarly, front plate 7 is preferably made of sections having like joints for aligning them. Although reflector plates of refractory material having ribbed faces are herein illustrated, sheet metal plates such as shown in Fig. 6 may be employed. the plates preferably being corrugated to provide a maximum surface area for heat reflection.

Referring to Fig. 4 of the drawing the structure there illustrated is a portable heater having a housing 20 provided with legs or supports 21, and having a closed top 22 and open sides 23 in the form of grids similar to the grid 3 shown in the heater of Figs. 1., 2 and 3. In this portable heater the reflector plates are shown as consisting of a central member 24 provided with a. thickened or flared upper portion 25 to afford curved surfaces for diverting the How of heated air to the sides of the heater at its top. The central iember 24 m ay be formed of refractory material and provided on both faces with ribs 26.

Adjacent to grids 23 there are reflector plates 27, narrower in vertical extent than central reflector 24 and arranged in a substantially central position with relation to reflector 24. Heater bars 30 are disposed between the central reflector plate 241- and the smaller plates 27 and spaced inwardly from the top and bottom. edges of the latter.

The structure shown in Fig. 5 is similar to that of Fig. i, differing from it in that a central reflecting member 31 is provided with a central flue or opening 32 for the flow of air from the bottom to the top of the heater, the heated air there being diverted outwardly by the top of the housing or casing and commingled with heated air passing between the reflector plates.

In the heater shown in Fig. 7, front reflector plates 40 are arranged one in front of each resistance element 41 with their tops inclined forwardly in louver form to afford free paths of flow for heated air. In this embodiment of the invention a large rear re flector plate 42 forms the back of the heater. A still further embodiment of the invention is shown in Fig. 8 which illustrates a heater differing from that of '7 in that it is provided with louver type reflector plates 44 between resistance elements 45 and a rear reflector plate 46.

When the electric resistors of the several forms of heaters become heated, the heat radiating from them is absorbed and reflected by the rear and front reflector plates which are provided with ribbed surfaces affording a relatively large surface area for absorbing and radiating a large amount of heat. This heat, as Well as direct heat from the resistors, is transmitted to air passing from the under side of the heater between the reflector plates to the upper region of the heater from which it passes outwardly through the grids. One of the principal features of the invention is that the construction and relative proportion of the reflector plates and the disposition of the heating elements between them is such as to prevent the direct radiation of heat from the heater elements. This avoids injury to furniture and utilizes the available heat for heating air which is directed into a room.

The function of the heater shown in Fig. 4 is the same a. that of Fig. l with the exception that two sets of heating elements are utilized. Each may be of the same capacity as the elements employed in the heater of Fig. 1, thereby doubling the heating capacity of the portable unit, or each may be proportionately smaller to provide the same amount of heat and cause it to emanate from both sides of the heater. In the type of heater shown in Fig. 5 the heat absorbed by the central reflector plate is partially conducted inwardly to flue 32 where it is transmitted to air passing upwardly through the flue. Otherwise, the heater functions the same as the heater of Fig. i in its production of heat by the elimination of direct radiation. In this type of heater shown in Figs. 7 and 8 the outer reflector plates are inclined to afford freer outward passage of heater air.

It is evident from the foregoing description of this invention that electrical heaters made in accordance therewith provide simple, durable and economical structures which may be designed to have ornamental appearances, and which are highly effective in the utilization of electrical current for heating purposes without liability of injury to surrounding objects. Although several embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

I claim:

1. An electric heater comprising a casing having an open vertical front for lateral dissipation of heat, front and rear reflecting plates arranged in said casing, and an electric resistance element disposed between said plates, said plates forming a passage for upward flow of air between them, and the front reflecting plate being disposed between said resistance element and said open front of the casing to prevent direct radiation of heat from the resistance element through the front.

2. An electric heater comprising a casing having an open Vertical front for lateral dissipation of heat, front and rear reflecting plates arranged in said casing, and an electric resistance element disposed between said plates, said plates forming a passage for flow of air between them from the bottom to the top of the casing, said front reflecting plate being disposed between said resistance ele ment and said open front of the casing to prevent direct radiation of heat from the resistance element through the front and said rear plate being curved outwardly at its top to direct heated air outwardly of the casing.

3. An electric heater comprising a casing having an open vertical front for lateral dissipation of heat. front and rear reflecting plates arranged in the casing and formed of adjoining sections, and a. horizontally disposed electric resistance element between said plates, said plates forming a passage for upward flow of air between them, and the front reflecting plate being disposed between said resistance element and said open front of the casting to prevent direct radiation of heat from the resistance element through the front.

4. An electric heater comprising a casing, a rear reflecting plate arranged in the easing, electric resistance elements extending horizontally in front of said rear reflecting plate, and reflecting plates arranged one in front of each of said resistance elements and forming with the rear reflecting plate passages for the upward floW of air.

5. An electric heater comprising a casing, a rear reflecting plate arranged in the casing, electric resistance elements extending horizontally in front of said rear reflecting plate, and reflecting plates arranged one in front of each of said resistance elements, said front reflecting plates being inclined to the Vertical with their upper edges outermost and forming with the rear reflecting plate passages for the upward flow of air.

6. An electric heater comprising a casing open at one side, a grid secured to the open side of the casing, a rear reflecting plate attached to the walls of said casing, electric resist-ance elements mounted in said casing in front of said rear plate, and a front reflecting plate secured in spaced relation to said rear plate and extending through the area of heat radiation of said electric resistance elements, said front and rear plates forming between them a passage for the upward flow of air.

In testimony whereof, I sign my name.

J AMES H. KNAPP. 

